<?php
$taartBeschikbaar = array(
    "mathijs"=>array(
        "from" => strtotime("1 September 2011 15:00"), // English month names 
        "to" => strtotime("1 September 2011 15:30"), // English month names 
    ),
   
);

$isTaart = false;

foreach ($taartBeschikbaar as $person=>$times) {
    if(time() >= $times['from'] && time() < $times['to']){
        $isTaart  = true;
    }
}    

?>
<html>
<head>
<title>Is er al taart?</title>
</head>
<body>

<h1>Is er al taart</h1>

<h2><?php print $isTaart?"ja":"nee"; ?></h2>

</body>
</html>